Effect of energy relaxation of H atoms at the wall on the production profile of H ions in large negative ion sources

Takado, Naoyuki*; Matsushita, Daisuke*; Fujino, Ikuro*; Hatayama, Akiyoshi*; Tobari, Hiroyuki; Inoue, Takashi

Production and transport process of the H atoms are numerically simulated using a three-dimensional Monte Carlo transport code. The code was applied to the "JAEA 10 ampere negative ion source" under Cs-seeded condition to obtain a spatial distribution of surface-produced H ions. In this analysis, we focus on the effect of the energy relaxation of the H atoms at the wall on the H ion production from the H atoms. The result indicates that, by considering the energy relaxation of the H atoms at the wall, the production profile of the surface-produced H ion is well reflected in the production profile of the H atom production.